Solar Hybrid Hot Water Controller For Your Hot Water Heater

Re: Solar Hybrid Hot Water Controller For Your Hot Water Heater

Thanks for all your comments and interest in the Solar Hybrid Hot Water Controller.

I can see why there may be some confusion. A "48V" Panel set like mine, using "12V" panels, will generally MPPT at about 65V to 70V and is around 80V open circuit.

The MPPT tries to get the most it can out of the panels, and it's pulsing so the voltage can go higher during the off period and then come down under load for that short period, so it all works out pretty well as the MPPT works it's magic.

Of course the higher voltage you go the better, but dedicating a simple, cheap two 24V panel set to your water heater is good for most people and cost effective.

The idea isn't perfection, it's how simple and hassle free can it be, and in the end does your upper element come on less for a total installed system cost around $700 ?

That beats most of the other systems out there. All DIY, easy install with no plumbing nightmare, no soldering, no leaks and no worry of freezing. Almost anyone can wire up 2 wires.

When I first started to want solar hot water I considered piping in a collector from outside. Then I watched videos and e-mailed a few guys that did that and found a few problems.

First, if you don't put in some sort of system to drain back the water you are going to have freeze problems and possible panel damage and leaks. Setting that up is not fun, you have problems with air in the system. It needs to be designed to totally drain or it will still have problems. And it still costs a lot and gets complicated. More stuff to worry about in the winter.

The other option is drain it every time the temp drops. Well, if you do that, there goes free winter hot water and what if you forget? I like simple and automatic stuff I don't have to mess with.

And then there's the plumbing, all over the place, maybe a 2nd exchange / heat storage tank that will develop leaks later as any tank does. And a pump that wears out or gets clogged. It's a maintenance nightmare and still a costly install.

So solar PV was the only way to go. I tried what XRinger is trying now, go direct to the element. But the mismatch in the morning and afternoon is brutal, the panels are nowhere near their MPP and you get little total daily heat that way unless you have the extra space and want to throw lots of panels at the problem and just say "oh well".

Another choice would be to change the element. Have you ever seen the nut size on those things? What if I screw up the threads? Will it leak later? Do I really want to mess with a perfectly working expensive tank?

And without MPPT, you still have a mismatch in the morning and afternoon anyway, doesn't really get that much better for all the hassle.

So I built the MPPT Hybrid system and love it! It's simple and just sits there quietly and works every day saving me money with no worries and little up front cost.

Installing wires instead of pipes is much easier, and it gives me other options, like if the grid goes down during a bad emergency I can say heck with hot water and simply re-configure the panels for 24V by switching a couple of connections and have more power for my emergency inverter and batteries.

Simple is better.

Thanks for your interest!